Intrapelvic Granuloma Formation Six Years after Total Hip Arthroplasty in a Dog

A 9-year-old Golden Retriever that had undergone left total hip arthroplasty 6 years previously was evaluated because of constipation and tenesmus. Abdominal radiography and ultrasonography revealed a large intrapelvic mass that was contiguous with a mass of polymethyl methacrylate that had been extruded through a defect in the medial wall of the acetabulum at the time of total hip arthroplasty. Clinical signs resolved following resection of the mass and associated polymethyl methacrylate from the pelvic canal. Results of histologic examination of the mass were consistent with a diagnosis of foreign body granuloma, most likely secondary to particulate debris. There was no clinical or radiographic evidence of aseptic loosening of the acetabular or femoral components, and the mass may have represented a response to wear debris.